The majority of domestic dishwashers currently in use have an adding device for holding one or more detergents, which are added to the wash liquor during the course of a wash cycle to clean the items to be washed that have been arranged in the dishwasher. Conventionally the detergent held in the adding device is discharged in its entirety into the wash compartment during the wash cycle and mixed in with the wash liquor circulating therein. In terms of its size the adding device is dimensioned so that the precise quantity of detergents required for a wash cycle can be introduced. The user of the dishwasher is therefore obliged to introduce the quantity of detergent required for the wash cycle into the adding device at the start of each wash cycle. This operation is inconvenient for the dishwasher user. There is also the problem with such dishwashers that the quantity of detergents introduced into the adding device can vary from user to user and from wash operation to wash operation. An incorrectly dosed quantity of detergent can result on the one hand in unsatisfactory wash results if too little detergent has been dosed and on other hand can result in a waste of detergents and an environmental burden, if too large a quantity of detergents has been dosed.
Adding devices which add the quantity of detergent stored therein to the wash liquor in one go also do not permit the execution of more complex wash programs. Thus for example in certain situations it can be expedient to add the detergent to the wash liquor at different times. Adding devices that are configured to hold a single dose of detergent cannot support such complex wash cycles.
With detergent dosing systems, in which a number of detergents are stored in different compartments of a cartridge or storage containers, the problem arises that when the addition of the detergent is controlled by sensor—depending on the degree of soiling of the wash liquor—the detergents can be used up at different times. In particular with cartridges, in which the chambers are arranged in a common housing of the cartridge, this can require a change of cartridge when some of the detergents have not yet been used up. This waste of detergents results in an environmental burden when the cartridge is disposed of by way of the garbage system for example.